The present invention is directed generally to a low profile cartridge and specifically to a low profile cartridge for an optical disk.
A number of disk-shaped optical storage media have been developed for use in storing various types of digital data in a manner such that the media can be readily removed from the read/write or drive device for which it is designed. A common type of optical media is second-surface optical media. In accordance with one definition, second-surface optical media can be defined in terms of the read operation that is conducted when reading information from the media. In particular, a second-surface optical medium can refer to a medium in which the read beam is incident on the substrate of the optical medium or disk before it is incident on the information content portions thereof.
The relatively thick and transparent substrate of second-surface optical media makes read-only or read-write operations relatively insensitive to dust particles, scratches and the like which are located more than 50 wavelengths from the information content portions thereof. On the other hand, the second-surface optical medium can be relatively sensitive to various optical aberrations. These optical aberrations include: (1) tilt of the substrate relative to the optical axis; (2) substrate thickness variations; and/or (3) substrate birefringence.
Another drawback associated with second-surface optical media is that the optical requirements of such media are substantially inconsistent with the miniaturization of the disk drive and optical components for such media. As will be appreciated, a longer working distance (distance between the objective lens and the information content portions) is required for an optical system that will read information from or write information onto second-surface media. This is due to the relatively thick transparent layer through which the radiation must pass to access the information content portions. To provide the longer working distance, larger optical components (e.g., objective lens) are required.
Because of these disadvantages associated with second-surface optical media, a first-surface optical medium has been devised by the assignee of the present application. Although it may be subject to more than one definition, in one embodiment, the first-surface optical medium refers to a medium in which the read beam during a read operation is incident on or impinges on information content portions of the first-surface optical medium before it impinges on a substrate of the first-surface optical medium.
The first-surface medium offers numerous advantages over a second-surface medium. By way of example, with the first-surface medium, the radiation does not pass through the relatively thick substrate so that there is a relatively shorter optical path, in comparison with second-surface medium, thereby providing a significantly shorter working distance, in comparison with second-surface medium. Since there is a shorter working distance, a smaller objective lens diameter, for a given numerical aperture, can be utilized which results in smaller, lower mass optical components to achieve a greater degree of optical drive miniaturization. Furthermore, the first-surface medium is not sensitive to substrate birefringence and substrate thickness variations. The first-surface medium is also much less sensitive to substrate tilt.
However, because there is no protective layer with a first-surface optical medium, to protect it from damage or being subject to unwanted particles or debris, it is imperative that a sufficiently protective housing or cartridge be employed to contain the optical medium. There are a number of factors to be considered in designing the protective cartridge for first-surface optical media. The cartridge should include a number of complementary and/or redundant protective features. For example, the cartridge should have features to protect the enclosed first-surface disk from damage such as by scratches and abrasions caused by handling of the cartridge or rotation of the enclosed disk during read and/or write operations. As will be appreciated, the cartridge should be designed to prevent contact of a surface of the cartridge with the operational surface of the disk. The cartridge should have features to retard the entry of dust and other foreign matter into the interior of the cartridge. Such foreign matter can prevent the optical head from reading information from or writing information to the disk. The cartridge should have a small form factor to permit the cartridge to be used with small, hand-held electronic devices, such as PEDs (Personal Electronic Devices) and digital cameras. The cartridge should have features to self-locate the cartridge in the disk drive. Such features facilitate proper alignment of the operational surface and data tracks relative to the optical head. The cartridge should also have features permitting the use of a double-sided, first-surface, optical disk. In other words, the cartridge should permit the optical head to access both of the opposing operational surfaces of the disk.
These and other design considerations are satisfied by one or more of the cartridge embodiments of the present invention.
In a first embodiment of the present invention, an apparatus for use in an optical system is provided. The apparatus includes a cartridge assembly having upper and lower shutter members that move independently of one another. In particularly preferred configuration, a single mechanism, such as a rotary arm mounted in the disk drive, engages and moves each of the shutter members. In one configuration, the mechanism engages and moves a first (but not a second) shutter member when the cartridge assembly is inserted into the disk drive in a first orientation and engages and moves the second (but not the first) shutter member when the cartridge assembly is inserted into the disk drive in a second orientation that is different from the first orientation. In one application, the first orientation is the flip side (or reverse) of the second orientation.
In another embodiment, a cartridge assembly is provided that includes a double-sided optical medium, access openings (for the optical head) located on opposing surfaces of the cartridge assembly, and one or more shutter members that are movably disposed to cover or uncover (simultaneously or sequentially) the access openings. In this manner, the cartridge assembly can be inserted into the disk drive in a first orientation to reveal a first operational surface of the medium and in a second orientation to reveal a second operational surface of the medium. As noted above, the first orientation can be the flip side (or reverse) of the second orientation.
In yet another embodiment, an apparatus for use in an optical system is provided.
The apparatus includes:
(a) an optical storage medium (which can be first- or second-surface) having at least a first side for storing information;
(b) a hub assembly operatively associated with the optical storage medium; and
(c) a cartridge assembly that contains the optical storage medium and the hub assembly. The cartridge assembly includes a first optical storage medium protector for use in safeguarding the optical storage medium against the occurrence of one or more unwanted events and a second optical storage medium protector for use in safeguarding the optical storage medium against the occurrence of one or more second unwanted events. The unwanted events, for example, can be contact of the operational surface of the disk with a cartridge wall(s) due to inward deflection of the cartridge wall(s) by a user, contact of the operational surface of the disk with the cartridge wall(s) during rotation of the disk by a disk drive, and collection of foreign matter on the disk operational surface.
The first and second optical storage medium protectors are preferably selected from a variety of features.
In one configuration, the first and/or second optical storage medium protectors include a first major wall (e.g., a shutter wall) covering a hub member of the hub assembly. Not only does the cartridge wall block foreign matter from entering into the interior of the cartridge through a hole in the cartridge wall(s) to permit the disk drive to engage the hub member, but also the hub member provides structural support to the wall to resist deflection. In one configuration, an inner surface of the first major wall is spaced from the adjacent outer surface of the hub member such that, when a force is applied to the wall, the interior surface contacts the outer surface of the hub member to thereby constrain inward wall deflection, but does not contact the operational surface of the optical storage medium.
In another configuration, the first and/or second optical storage medium protectors include a locking subassembly having first and second positions. When the locking subassembly is in the first position, access to the hub member and/or optical storage medium is blocked (e.g., by a movable shutter wall member) and when the locking subassembly is in the second position access to the hub member and/or optical storage medium is available. In one design, a laterally movable wall or shutter is disposed so as to cover an access door in the cartridge wall for the optical head, as well as an opening in the cartridge wall for the hub member, in the first position and uncover the access door for the optical head, and the opening for the hub member, in the second position.
In yet another configuration, the cartridge assembly further includes a third optical storage medium protector. The third optical storage medium protector includes a medium constraining member having portions that overlie a peripheral edge of the optical storage medium. The third optical storage medium protector can be a annular slot positioned around the periphery of the medium for receiving a peripheral edge of the medium in between opposing surfaces of the slot. The opposing surfaces of the slot are interiorly offset from a surface of a wall of the cartridge to suspend the medium above, and avoid contact of the medium with the interior surface.
In yet another embodiment, an apparatus for use in an optical system is provided. The apparatus includes:
(a) a hub assembly having a total height and including at least a first hub member, with the total height including at least a height of the first hub member;
(b) an optical storage medium having a thickness and including a first side and a second side, with at least the first side storing information; and
(c) a cartridge assembly for containing the hub assembly and the optical storage medium. The cartridge assembly has a low profile. The ratio of the cartridge assembly height to the total height of the hub assembly is typically less than about 1.50 and more typically ranges from greater than 1.00 to about 1.25.
In yet a further embodiment, an apparatus for use in an optical system is provided. The apparatus includes:
(a) an optical storage medium; and
(b) a cartridge assembly including a holding feature (e.g., at least one of a locating pin and a locating hole) and a displacement feature (e.g., at least one of an anti-rotational pin and an anti-rotational slot). In one configuration, one of the locating pin and hole and one of the anti-rotational pin and slot are each located on the disk drive with the other being located on the cartridge housing. The anti-rotational slot has a larger cross-sectional extent or area than the locating hole to permit the disk drive to displace the cartridge housing along an arc extending along the anti-rotational slot (e.g., rotate the housing), the center of which is located at the center of the locating pin. In this manner, the disk drive is able to displace the cartridge housing as needed to correctly align the cartridge in a plane parallel to an operational surface of the medium. In another configuration, the disk drive includes one or more datum features (e.g., one or more contact surfaces) for contacting one or more surfaces of the cartridge assembly to correctly position the cartridge in a plane normal to the operational surface of the medium. These features facilitate alignment of the medium in the plane for substantially optimal focus and servo control.
In yet a further embodiment, a method is provided for safeguarding an optical storage medium. The method includes the steps of:
(a) providing a cartridge assembly including a housing having a major wall with an inner wall surface and containing (i) an optical storage medium side and (ii) a hub assembly joined to the optical storage medium, with one or more portions of the major wall covering a first hub member of the hub assembly; and
(b) opening a locking subassembly when access to the optical storage medium is being provided.
In yet another embodiment, an apparatus for use in an optical system is provided that includes:
(a) an optical storage medium having at least one operational surface for storing information; and
(b) a cartridge assembly that contains the optical storage medium and includes a lockout subassembly. The cartridge assembly is properly insertable into a disk drive in a first orientation and improperly insertable into the disk drive in a second orientation. The lockout subassembly permits the cartridge assembly to be inserted fully into the disk drive in the first orientation and retards the cartridge assembly from being inserted fully into the disk drive in the second orientation.
In one configuration, the lockout subassembly includes a slot for engaging a rotary arm located in the disk drive, thereby inhibiting full insertion of the cartridge assembly in the second orientation. The cartridge assembly can include a second lockout subassembly located on an opposing side of the cartridge assembly from the first lockout subassembly to safeguard the cartridge from being improperly inserted when the cartridge assembly is flipped over.
As will be appreciated, the foregoing summary of the invention is neither exhaustive nor complete. Other embodiments including one or more of the features referred to above and/or one or more of the features discussed below are envisioned by the present disclosure.